Angle Finder Calculator
inside or outside corner
Select = 1
Left = 7
Rake = 10
Find an angle given left, right and rake (hypotenuse) sides of a triangle.
Changing one variable will make the buttons of the other variables change to this [icon--app-unknown-inverse] select the one you would like to re-calculate.
Contributed by Gary Wiese.
The Left side already has a value of 7in and the Rake is 10in, but these are only default settings which can be changed at any time. The reason for the defaults is because those two variables will not change very often while the Right side will change with each measurement.
Select Inside Corner from the list above:
From the corner out along the left side mark it at 7in, then take the 10in stick or scrape and place one end at the 7in mark and use it to mark the right side. Then measure out from the corner to that measurement on the right side and enter it into the template. Those three measurements will be used to find the Angle.
Using a 10in stick with the 7in mark on it makes it easier to measure all the corners. Basically your only measuring the Right side every time because the Left side and the Rake will stay the same with each measurement.
Enter 8in to the Right label on the template.
You can also change the angle. Change Angle to 125°.
Now select the Right button to calculate: 4&3/16in.
This template measures one angle to find another angle. More specifically your measurements are used to find Angle C, which is then used to find Angle D. Angles C and D are called Supplementary Angles, meaning they add to 180°. So by finding Angle C, Angle D is calculated using the equation D = 180 - C.
Extend a straight edge past the corner a desired amount, enter that into the Left label of the template. Measure from the outside of the corner another amount enter that into the Right Label of the template. Measure the distance from that mark to the end of the straight edge sticking out past the corner, enter that into the Rake Label on the template.
Select Outside Corner from the list at the top.
The Angle is 85°.
Laying Out Lines
You may just want to layout some lines. You are given the angles. The best way to do this is to enter the Right and Left first then the Angle, then select the button next to Rake.
Once the first line is snapped, mark on that line from the vertex the Left value and place a nail there and at the vertex. Then from the vertex the length of the Right value draw an arc. Hook your tape on the first nail on the Left line and stretch your tape out the length of the Rake and draw an arc that bisects the arc on the Right. Now you can snap a line from the vertex to where both arcs intersect.
You have a couple walls that need to be at 120° and others that are at 90° and 110° and so on.
The Rake is 12ft 1&1/2in.
The Rake is 9ft 10&13/16in.
The Rake is 9ft 3/8in.